Connecticut Senator Chris Murphy led a 15-hour filibuster with a pledge that he would press a legislative response to the Pulse nightclub massacre, in Orlando, FL. The Irish American Senator, who has long been pushing for a reform of gun laws in the United States, said he was upset with the congressional inaction on gun violence and lack of debate.

Murphy and his fellow Democrats' 15 hours pave the way for high-profile congressional votes on restricting firearms days after the worst mass shooting in United States history. Early on Sunday morning, Omar Mateen, a 29-year-old US citizen killed 49 people and injured 53 when he opened fire, using automatic weapons, in a gay nightclub.

The Connecticut Senator was joined on the floor by 38 other Democrat Party speakers during his filibuster, one of the longest in US history. Senators Cory Booker (D-NJ) and Sen. Richard Blumenthal (D-Conn.) stood with Murphy for hours on end.

Here ya go @so_manybees

The #filibuster participants as of 1AM est

— arielkins (@arielkins) June 16, 2016
Murphy has been battling with gun control reform since the mass murder of 20 young children in Newtown, CT, in 2012.

He began his marathon filibuster saying “I’ve had enough.

“I’m going to stand here and hold the floor while we give our colleagues time to try to find a path forward.”

After 15 hours as he stepped down he said Republican leaders had committed to hold vote on expanded gun background checks and a ban on gun sales to suspected terrorists.

This proposal from Senator Dianne Feinstein (D-Calif.), to bar those on federal terror watch lists from obtaining firearms, and a plan from Murphy and Senators Cory Booker (D-N.J.) and Chuck Schumer (D-N.Y.) mandating background checks for sales at gun shows and over the Internet.

Mateen, the perpetrator in the Orlando massacre, had been flagged by the FBI multiple times but was ultimately removed from a watch list and was able to purchase firearms legally.

Republicans are expected to put forward their own proposals for votes.

At 2.11am Murphy delivered an emotional tribute to two Sandy Hook victims Dylan Hockley (6) and teacher’s aide, Anne Marie Murphy, who was killed while trying to shield Hockley from the gun shots.

Read more: Anne Marie Murphy died ‘serving children and serving God’ in Newtown tragedy

The Senator said “It doesn’t take courage to stand here on the floor of the United States Senate for two hours or six hours or 14 hours.”

“If Anne Marie Murphy could do that, then ask yourself: What can you do to make sure that Orlando or Sandy Hook never, ever happens again?”

However, it’s suspected that behind closed doors bipartisan negotiations on gun legislation were breaking down even while Murphy filibustered. Aides from both parties told Politico there was little real movement and both remained firm on their previous positions as both parties were briefed by FBI Director James Comey.

In December 2015 Republican and Democrats developed anti-terror gun proposals after the mass shooting in San Bernardino, CA, when 14 people were killed and 22 were seriously injured. One Democratic source said it would be a breakthrough to get re-dos on those failed votes. They said “My guess is we’re back to square one.”

On Thursday morning, after the filibuster, Murphy spoke to CNN’s “New Day.” He explained that he went down to the floor because “there was nothing that was going to happen in the United States Senate, no debate, in the wake of the worst mass shooting in American history, until this filibuster began. That was deeply offensive to many of us, in the sense that we forced that debate.”

He added that the reason the Democrats were responding so aggressively was due to a desire to find a solution.

“The families coming out of Orlando are going to be fighting for laws that will prevent a multitude of other gun tragedies around the country."

Murphy pointed out "There are 80 people dying every single day. There is the equivalent of an Orlando and a half every day in this country. We can't accept that the only points we have are these mass shootings.”